1997 chevy lumina catalytic converter replacement

What is involved in replacing a catalytic converter and how much would it cost for a new one? Can i do it without taking out engine mounts?

its pretty straight foward,the removal is the hardest dealing with old clamps if you have a torch this will help alot.if not you can cut slits in it with hacksaw.aftermarket prices i'd say 100-150

Since I'm going to have to do this in the spring for the E-test, I thought I'd have a look at mine:

Here is a photo:

http://www.qzoka.com/images/isnxtbq5i9yt9r3adt6.jpg

Its hard to believe, but those are probably supposed to be four nuts/bolts holding the Catconverter (left) to the exhaust tail bracket (right) welded to the trailing exhaust pipe.

The probable reason for this arrangement is simple. Heating up the Cat Converter with a welding torch probably damages it.

So the cat converter comes pre-welded to the front-pipe, which is bolted to the exhaust manifold coming from the engine (there will be some kind of asbestos sealing ring too). Then the rear of the Cat Converter is bolted to the plate (shown rusted out here) that has been previously welded to the rest of the exhaust system.

Thus, if you order a cat converter for this system, an arrangement like the following is probably easiest:

Get one with the manifold pipe attached. prewelded, and the plate on the rear.

They have one for $106 here:

http://cpwstore.carpartswholesale.com/catalog/?N=4294966939+1588+9939+4294967219+2268

You can see from the picture that you just need to unscrew the bolts at each end and replace them afterward.

You want to try to avoid welding if possible, so as not to damage your new converter.

Is it easier to take off the hardware mounting the flange to the exhaust manifold from under the car or to just do it from under the hood? What gaskets are inbetween the exhaust manifold flange and the flange on the pipe before the converter? I am having a hard time tracking those down. How many are there and does anyone have part numbers?